docs: def write_transcriptions(utterances: List[Utterance],
                           tgt_dir: Path, ext: str, lazy: bool) -> None:
      """ Write the utterance transcriptions to files in the tgt_dir. Is lazy and
      checks if the file already exists.
  
      Args:
          utterances: A list of Utterance objects to be written.
          tgt_dir: The directory in which to write the text of the utterances,
              one file per utterance.
          ext: The file extension for the utterances. Typically something like
              "phonemes", or "phonemes_and_tones".
  
      """
  
      tgt_dir.mkdir(parents=True, exist_ok=True)
      for utter in utterances:
          out_path = tgt_dir / "{}.{}".format(utter.prefix, ext)
          if lazy and out_path.is_file():
              continue
          with out_path.open("w") as f:
              print(utter.text, file=f)